substr() — internals

substr() — internals

Where it lives

• Signature: src/builtins/string/substr.rs
• Lowering: src/codegen/lower_inst/builtins/strings.rs:775 (lower_substr)
• Function symbol: lower_substr()

Lowering notes

• Lowers substr(string, offset, length?) with target-local pointer arithmetic.

Runtime helpers

The following runtime helpers are referenced:

• __rt_substr_replace

Signature summary

function substr(string $string, int $offset, int $length = null): string

What the type checker enforces

• Arity: takes 2–3 arguments (1 optional).

Eval interpreter (magician)

• Declaration: crates/elephc-magician/src/interpreter/builtins/string/substr.rs (eval_builtin!)
• Dispatch hooks: direct, values

Cross-references

• User reference for substr()